If you float an aluminum pie plate on the surface of a pond and move the north pole of a strong magnet in a clockwise circle just above that plate, the plate will
A) begin turning counter-clockwise, as though it were being twisted away from the magnet.
B) begin turning clockwise, as though it were being dragged along with the magnet.
C) remain stationary.
D) be lifted out of the water and will stick to the strong north pole above it.

Question

Quizplus · Accepted Answer

The aluminum pie plate will begin turning clockwise, following the motion of the magnet. This occurs due to electromagnetic induction, where the moving magnetic field induces eddy currents in the conductive aluminum plate. These currents create their own magnetic field, which interacts with the original magnetic field of the magnet, causing the plate to move in the direction of the magnet's movement.

If You Float an Aluminum Pie Plate on the Surface